Combination Of Refastenable And Releasable Bonds

ABSTRACT

A refastenable, pant-like garment, including a chassis including a first waist region and a second waist region, together defining a waist opening and first and second leg openings. The garment also includes a first refastenable seam joining a first distal portion of the first waist region to a first distal portion of the second waist region. The first refastenable seam includes a first refastenable bond connecting the first distal portion of the first waist region and the first distal portion of the second waist region having a first refastenable bond peel strength.

This application is a divisional of application Ser. No. 11/215,865entitled Combination of Refastenable and Releasable Bonds and filed inthe U.S. Patent and Trademark Office on Aug. 30, 2005. The entirety ofthe prior application is hereby incorporated by reference in thisapplication.

BACKGROUND

Pant-like absorbent garments, such as adult incontinence wear, infantand children's diapers, swim wear and training pants, typically haveadhesive or mechanical fasteners on the sides for donning and removal,or else rely on a stretchable waist opening and leg openings to slide onand off the wearer. Absorbent garments that slide on and off a wearercan be messy after use. Furthermore, in order to remove such absorbentgarments, the wearer's clothing covering the absorbent garments, such aspants, must generally be completely removed. Checking the status of thewearer's absorbent garment contents can be just as cumbersome aschanging the absorbent garment.

Refastenable seams including mechanical fasteners, such as, for example,hook and loop fasteners, have been found to be particularly beneficialwhen used in conjunction with pant-like absorbent garments. Refastenableseams allow for the garment to be easily applied and removed, as well asperiodically opened to check for exudates and closed if no exudates arefound.

Refastenable seams generally perform much better in shear than in peel.However in the manufacturing process butt seam are generally lesscomplicated to construct than lap seams. Butt seams are stressedpredominantly in peel, while lap seams are stressed predominantly inshear. As a result, there is a need or desire for refastenable seam thatcan be constructed as a butt seam but will convert to a lap seam.

SUMMARY

In response to the foregoing need, the present inventor undertookintensive research and development efforts that resulted in thediscovery of a combination of refastenable and releasable bond. Oneversion of the present invention includes a prefastened article,including a chassis including a first waist region and a second waistregion, together defining a waist opening and first and second legopenings. The article also includes a refastenable seam joining a firstdistal portion of the first waist region to a first distal portion ofthe second waist region. The refastenable seam includes a firstrefastenable bond connecting the first distal portion of the first waistregion and the first distal portion of the second waist region having afirst refastenable bond peel strength. The first distal portion of thefirst waist region is folded and bonded with a releasable bond having afirst releasable bond peel strength. Further the first refastenable bondpeel strength is greater than the first releasable bond peel strength.

Another version of the present invention provides a refastenable,pant-like garment, including a chassis including a first waist regionand a second waist region, together defining a waist opening and firstand second leg openings. The garment also includes a first refastenableseam joining a first distal portion of the first waist region to a firstdistal portion of the second waist region. The first refastenable seamincludes a first refastenable bond connecting the first distal portionof the first waist region and the first distal portion of the secondwaist region having a first refastenable bond peel strength. The firstdistal portion of the first waist region being folded and bonded with areleasable bond having a first releasable bond peel strength. Furtherthe first refastenable bond peel strength is greater than the firstreleasable bond peel strength. The garment also includes a secondrefastenable seam joining a second distal portion of the first waistregion to a second distal portion of the second waist region. The secondrefastenable seam includes a second refastenable bond connecting thesecond distal portion of the first waist region and the second distalportion of the second waist region having a second refastenable bondpeel strength. The second distal portion of the first waist region beingfolded and bonded with a releasable bond having a second releasable bondpeel strength. Further the second refastenable bond peel strength isgreater than the second releasable bond peel strength. Still anotherversion of the present invention includes a refastenable joint joining afirst material having a first end and a second end to a second materialhaving a third end and a fourth end. The refastenable joint including arefastenable bond connecting the first end to the third end. The firstmaterial is folded and bonded with a releasable bond. Further separatingthe second end from the fourth end initially stresses the refastenablebond and the releasable bond predominantly in peel, then ruptures thereleasable bond predominantly in peel, then stresses the refastenablebond predominantly in shear.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an absorbent garment having refastenableside seams;

FIG. 2 is a plan view of an absorbent garment in a stretched flat stateshowing the surface of the garment that faces away from the wearer whenthe garment is worn;

FIG. 3 is a plan view of an absorbent garment in a stretched flat stateshowing the surface of the garment that faces the wearer when thegarment is worn, and with portions cut away to show the underlyingfeatures;

FIGS. 4 and 4A illustrate top views of a waist region of an absorbentgarment illustrating a first version of refastenable seams of thepresent invention;

FIGS. 5 and 5A illustrate top views of a waist region of an absorbentgarment illustrating a second version of refastenable seams of thepresent invention;

FIGS. 6A-6D illustrate several seams joining a first material to asecond material 116.

DEFINITIONS

Within the context of this specification, each term or phrase below willinclude the following meaning or meanings.

“Attached” refers to the joining, adhering, connecting, bonding, or thelike, of at least two elements. Two elements will be considered to beattached to one another when they are attached directly to one anotheror indirectly to one another, such as when each is directly connected tointermediate elements.

“Bonded” refers to the joining, adhering, connecting, attaching, or thelike, of at least two elements. Two elements will be considered to bebonded together when they are bonded directly to one another orindirectly to one another, such as when each is directly bonded tointermediate elements.

“Elastomeric” and “elastic” refer to that property of a material orcomposite by virtue of which it tends to recover its original size andshape after removal of a force causing a deformation. It is generallypreferred that the elastomeric material or composite be capable of beingelongated by at least 50 percent, more preferably by at least 300percent, of its relaxed length and recover, upon release of an appliedforce, at least 50 percent of its elongation.

“Film” refers to a thermoplastic film made using a film extrusionprocess, such as a cast film or blown film extrusion process. The termincludes apertured films, slit films, and other porous films whichconstitute liquid transfer films, as well as films which do not transferliquid.

“Hydrophilic” describes fibers or the surfaces of fibers which arewetted by the aqueous liquids in contact with the fibers. The degree ofwetting of the materials can, in turn, be described in terms of thecontact angles and the surface tensions of the liquids and materialsinvolved. Equipment and techniques suitable for measuring thewettability of particular fiber materials or blends of fiber materialscan be provided by a Cahn SFA-222 Surface Force Analyzer System, or asubstantially equivalent system. When measured with this system, fibershaving contact angles less than 90 are designated “wettable” orhydrophilic, while fibers having contact angles greater than 90 aredesignated “nonwettable” or hydrophobic.

“Layer” when used in the singular can have the dual meaning of a singleelement or a plurality of elements.

“Liquid impermeable,” when used in describing a layer or multi-layerlaminate, means that a liquid, such as urine, will not pass through thelayer or laminate, under ordinary use conditions, in a directiongenerally perpendicular to the plane of the layer or laminate at thepoint of liquid contact.

“Liquid permeable material” or “liquid water-permeable material” refersto a material present in one or more layers, such as a film, nonwovenfabric, or open-celled foam, which is porous, and which is waterpermeable due to the flow of water and other aqueous liquids through thepores. The pores in the film or foam, or spaces between fibers orfilaments in a nonwoven web, are large enough and frequent enough topermit leakage and flow of liquid water through the material.

“Longitudinal” and “transverse” have their customary meaning, asindicated by the longitudinal and transverse axes depicted in FIGS. 2and 3. The longitudinal axis lies in the plane of the article and isgenerally parallel to a vertical plane that bisects a standing wearerinto left and right body halves when the article is worn. The transverseaxis lies in the plane of the article generally perpendicular to thelongitudinal axis. The article as illustrated is generally longer in thelongitudinal direction than in the transverse direction, althoughproducts longer in the transverse direction are also possible.

“Longitudinal midline” refers to a line, either real or imaginary, thatruns along the longitudinal length of the chassis of an absorbentgarment and bisects the chassis into two halves of equal transversewidth.

“Meltblown fiber” means fibers formed by extruding a moltenthermoplastic material through a plurality of fine, usually circular,die capillaries as molten threads or filaments into converging highvelocity heated gas (e.g., air) streams which attenuate the filaments ofmolten thermoplastic material to reduce their diameter, which may be tomicrofiber diameter. Thereafter, the meltblown fibers are carried by thehigh velocity gas stream and are deposited on a collecting surface toform a web of randomly dispersed meltblown fibers. Such a process isdisclosed for example, in U.S. Pat. No. 3,849,241 to Butin et al.Meltblown fibers are microfibers which may be continuous ordiscontinuous, are generally smaller than about 0.6 denier, and aregenerally self bonding when deposited onto a collecting surface.Meltblown fibers used in the present invention are preferablysubstantially continuous in length.

“Member” when used in the singular can have the dual meaning of a singleelement or a plurality of elements.

“Nonwoven” and “nonwoven web” refer to materials and webs of materialwhich are formed without the aid of a textile weaving or knittingprocess.

“Offset tucked” refers to a folded position of a garment wherein thefront and back regions of the garment are skewed such that thelongitudinal midline of the front region of the chassis is offset or notaligned with the longitudinal midline of the back region of the chassis,and seams connecting the front and back regions are tucked.

“Operatively joined,” in reference to the attachment of an elasticmember to another element, means that the elastic member when attachedto or connected to the element, or treated with heat or chemicals, bystretching, or the like, gives the element elastic properties; and withreference to the attachment of a non-elastic member to another element,means that the member and element can be attached in any suitable mannerthat permits or allows them to perform the intended or describedfunction of the joinder. The joining, attaching, connecting or the likecan be either directly, such as joining either member directly to anelement, or can be indirectly by means of another member disposedbetween the first member and the first element.

“Permanently attached” or “permanently bonded” refers to the joining,adhering, connecting, attaching, bonding, or the like, of two elementsof an absorbent garment such that the elements tend to be and remainattached during normal use conditions of the absorbent garment.

“Polymers” include, but are not limited to, homopolymers, copolymers,such as for example, block, graft, random and alternating copolymers,terpolymers, etc. and blends and modifications thereof. Furthermore,unless otherwise specifically limited, the term “polymer” shall includeall possible geometrical configurations of the material. Theseconfigurations include, but are not limited to isotactic, syndiotacticand atactic symmetries.

“Refastenable” refers to the property of two elements being capable ofreleasable attachment, separation, and subsequent releasablereattachment without substantial permanent deformation or rupture. Therefastenable elements can be attached, separated and reattached for atleast one cycle, suitably for at least 5 cycles, or suitably for atleast 10 cycles.

“A Releasable bond” and variations thereof refer to two elements beingconnected or connectable such that the elements tend to remain connectedabsent a separation force applied to one or both of the elements. Therequired separation force is typically less than that encountered whilewearing the absorbent garment.

“Self-engaging fastener” refers to a fastening component that can engagewith another fastening component having the same structure.

“Spunbonded fiber” refers to small diameter fibers which are formed byextruding molten thermoplastic material as filaments from a plurality offine capillaries of a spinnerette having a circular or otherconfiguration, with the diameter of the extruded filaments then beingrapidly reduced as by, for example, in U.S. Pat. No. 4,340,563 to Appelet al., and U.S. Pat. No. 3,692,618 to Dorschner et al., U.S. Pat. No.3,802,817 to Matsuki et al., U.S. Pat. Nos. 3,338,992 and 3,341,394 toKinney, U.S. Pat. No. 3,502,763 to Hartmann, U.S. Pat. No. 3,502,538 toPetersen, and U.S. Pat. No. 3,542,615 to Dobo et al., each of which isincorporated herein in its entirety by reference. Spunbond fibers arequenched and generally not tacky when they are deposited onto acollecting surface. Spunbond fibers are generally continuous and oftenhave average deniers larger than about 0.3, more particularly, betweenabout 0.6 and 10.

“Stretchable” means that a material can be stretched, without breaking,to at least 150% of its initial (unstretched) length in at least onedirection, suitably to at least 250% of its initial length, desirably toat least 300% of its initial length.

“Superabsorbent” or “superabsorbent material” refers to awater-swellable, water-insoluble organic or inorganic material capable,under the most favorable conditions, of absorbing at least about 15times its weight and, more desirably, at least about 30 times its weightin an aqueous solution containing 0.9 weight percent sodium chloride.The superabsorbent materials can be natural, synthetic and modifiednatural polymers and materials. In addition, the superabsorbentmaterials can be inorganic materials, such as silica gels, or organiccompounds such as cross-linked polymers.

“Surface” includes any layer, film, woven, nonwoven, laminate,composite, or the like, whether pervious or impervious to air, gas,and/or liquids.

“Thermoplastic” describes a material that softens when exposed to heatand which substantially returns to a nonsoftened condition when cooledto room temperature.

These terms may be defined with additional language in the remainingportions of the specification.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

The present invention is directed to refastenable seams on garments. Theprinciples of the present invention can be incorporated into anysuitable disposable absorbent article having a pre-fastened andrefastenable seam. Examples of such suitable articles include diapers,training pants, incontinence products, other personal care or healthcare garments, including medical garments, or the like. As used herein,the term “incontinence products” includes absorbent underwear forchildren, absorbent garments for children or young adults with specialneeds such as autistic children or others with bladder/bowel controlproblems as a result of physical disabilities, as well as absorbentgarments for incontinent older adults. For ease of explanation, thedescription hereafter will be in terms of a child's training pant.

Referring to FIG. 1, the training pant 20 includes an absorbent chassis32 defining a front region 22, a back region 24, a crotch region 26interconnecting the front and back regions, an inner surface 28 which isconfigured to contact the wearer, and an outer surface 30 opposite theinner surface which is configured to contact the wearer's clothing. Withadditional reference to FIGS. 2 and 3, the absorbent chassis 32 alsodefines a pair of transversely opposed distal edges 36 and a pair oflongitudinally opposed waist edges, which are designated front waistedge 38 and back waist edge 39. The front region 22 is contiguous withthe front waist edge 38, and the back region 24 is contiguous with theback waist edge 39. The chassis 32 also includes a pair of transverselyopposed front side panels 34 and a pair of transversely opposed backside panels 134. The front and back side panels 34, 134 are formed alongthe distal edges 36 of the chassis and can either be integrally formedwith the chassis, as shown in FIG. 2, or can each include at least oneseparate element permanently attached to the chassis, as shown in FIGS.1 and 3. For reference, arrows 48 and 49 depicting the orientation ofthe longitudinal axis and the transverse axis, respectively, of thetraining pant 20 are illustrated in FIGS. 2 and 3.

The illustrated absorbent chassis 32 can include an outer cover 40, abodyside liner 42 which is connected to the outer cover in a superposedrelation, an absorbent assembly 44 which is located between the outercover 40 and the bodyside liner 42, and a pair of containment flaps 46,as shown in FIG. 3.

With the training pant 20 in the fastened position, as partiallyillustrated in FIG. 1, the front and back regions 22 and 24 are joinedtogether to define a three-dimensional pant configuration having a waistopening 50 and a pair of leg openings 52. The front region 22 includesthe portion of the training pant 20 which, when worn, is positioned onthe front of the wearer while the back region 24 includes the portion ofthe training pant which, when worn, is positioned on the back of thewearer. The crotch region 26 of the training pant 20 includes theportion of the training pant which, when worn, is positioned between thelegs of the wearer and covers the lower torso of the wearer. The frontand back side panels 34, 134 include the portions of the training pant20 which, when worn, are positioned on the hips of the wearer.

As shown in FIG. 3, the front region 22 of the absorbent chassis 32includes the transversely opposed front side panels 34 and a front panel35 positioned between and interconnecting the side panels, along with afront waist elastic member 54 and any other connected components. Afront waist region 90 is a region of the front panel 35 along the frontwaist edge 38. The back region 24 of the absorbent chassis 32 includesthe transversely opposed back side panels 134 and a back panel 135positioned between and interconnecting the side panels, as well as arear waist elastic member 56 and any other connected components. A backwaist region 92 is a region of the back panel 135 along the back waistedge 39. The waist edges 38 and 39 of the absorbent chassis 32 areconfigured to encircle the waist of the wearer when worn and provide thewaist opening 50 which defines a waist perimeter dimension. Portions ofthe transversely opposed distal edges 36 of the chassis 32 in the crotchregion 26, along with leg end edges 70 of the side panels 34 and 134,generally define the leg openings 52.

The absorbent chassis 32 is configured to contain and/or absorb any bodyexudates discharged from the wearer. For example, the absorbent chassis32 desirably, although not necessarily, includes the pair of containmentflaps 46 which are configured to provide a barrier to the transverseflow of body exudates. A flap elastic member 53 (FIG. 3) can beoperatively joined with each containment flap 46 in any suitable manneras is well known in the art. The elasticized containment flaps 46 definean unattached edge which assumes an upright, generally perpendicularconfiguration in at least the crotch region 26 of the training pant 20to form a seal against the wearer's body. The containment flaps 46 canbe located along the transversely opposed distal edges 36 of theabsorbent chassis 32, and can extend longitudinally along the entirelength of the absorbent chassis or may only extend partially along thelength of the absorbent chassis. Suitable constructions and arrangementsfor the containment flaps 46 are generally well known to those skilledin the art and are described in U.S. Pat. No. 4,704,116 issued Nov. 3,1987 to Enloe, which is incorporated herein by reference.

To further enhance containment and/or absorption of body exudates, thetraining pant 20 can include the front waist elastic member 54, the rearwaist elastic member 56, and leg elastic members 58, as are known tothose skilled in the art (FIG. 3). The waist elastic members 54 and 56can be operatively joined to the outer cover 40 and/or bodyside liner 42along the opposite waist edges 38 and 39 as well as over waist edges 72of the side panels 34, 134, and can extend over part or all of the waistedges. The leg elastic members 58 can be operatively joined to the outercover 40 and/or bodyside liner 42 while longitudinally aligned along thedistal edges 36 and positioned in the crotch region 26 of the chassis32.

The flap elastic members 53, the waist elastic members 54 and 56, andthe leg elastic members 58 can be formed of any suitable elasticmaterial. As is well known to those skilled in the art, suitable elasticmaterials include sheets, strands or ribbons of natural rubber,synthetic rubber, or thermoplastic elastomeric polymers. The elasticmaterials can be stretched and adhered to a substrate, adhered to agathered substrate, or adhered to a substrate and then elasticized orshrunk, for example with the application of heat; such that elasticconstrictive forces are imparted to the substrate. In one particularembodiment, for example, the leg elastic members 58 include a pluralityof dry-spun coalesced multifilament spandex elastomeric threads soldunder the trade name LYCRA® and available from E.I. DuPont de Nemoursand Company, Wilmington, Del., U.S.A.

The outer cover 40 desirably includes a material that is substantiallyliquid impermeable, and can be elastic, stretchable or nonstretchable.The outer cover 40 can be a single layer of liquid impermeable material,but desirably includes a multi-layered laminate structure in which atleast one of the layers is liquid impermeable. For instance, the outercover 40 can include a liquid permeable outer layer and a liquidimpermeable inner layer that are suitably joined together thermally,ultrasonically, by a laminate adhesive, or by any other suitable methodsknown in the art. Suitable laminate adhesives, which can be appliedcontinuously or intermittently as beads, a spray, parallel swirls, orthe like, can be obtained from Findley Adhesives, Inc., of Wauwatosa,Wis., U.S.A., or from National Starch and Chemical Company, Bridgewater,N.J., U.S.A. The liquid permeable outer layer can be any suitablematerial and desirably one that provides a generally cloth-like textureand/or mating fastening component qualities. One example of such amaterial is a 20 gsm (grams per square meter) spunbond polypropylenenonwoven web. The outer layer may also be made of those materials ofwhich liquid permeable bodyside liner 42 is made. While it is not anecessity for the outer layer to be liquid permeable, it is desired thatit provides a relatively cloth-like texture to the wearer.

The inner layer of the outer cover 40 can be both liquid and vaporimpermeable, or can be liquid impermeable and vapor permeable. The innerlayer is desirably manufactured from a thin plastic film, although otherflexible liquid impermeable materials may also be used. The inner layer,or the liquid impermeable outer cover 40 when a single layer, preventswaste material from wetting articles, such as bedsheets and clothing, aswell as the wearer and care giver. A suitable liquid impermeable filmfor use as a liquid impermeable inner layer, or a single layer liquidimpermeable outer cover 40, is a 0.2 millimeter polyethylene filmcommercially available from Huntsman Packaging of Newport News, Va.,U.S.A. If the outer cover 40 is a single layer of material, it can beembossed and/or matte finished to provide a more cloth-like appearance.As earlier mentioned, the liquid impermeable material can permit vaporsto escape from the interior of the disposable absorbent article, whilestill preventing liquids from passing through the outer cover 40. Asuitable “breathable” material is composed of a microporous polymer filmor a nonwoven fabric that has been coated or otherwise treated to imparta desired level of liquid impermeability. A suitable microporous film isa PMP-1 film material commercially available from Mitsui ToatsuChemicals, Inc., Tokyo, Japan, or an XKO-8044 polyolefin filmcommercially available from 3M Company, Minneapolis, Minn.

The liquid permeable bodyside liner 42 is illustrated as overlying theouter cover 40 and absorbent assembly 44, and may but need not have thesame dimensions as the outer cover 40. The bodyside liner 42 isdesirably compliant, soft feeling, and non-irritating to the child'sskin. Further, the bodyside liner 42 can be less hydrophilic than theabsorbent assembly 44, to present a relatively dry surface to the wearerand permit liquid to readily penetrate through its thickness. Asmentioned, the bodyside liner 42 and/or the outer cover 40 can be madeof a fastening component material or a mating fastening componentmaterial to eliminate the need for separately attached mating fasteningcomponents.

The bodyside liner 42 can be manufactured from a wide selection of webmaterials, such as synthetic fibers (for example, polyester orpolypropylene fibers), natural fibers (for example, wood or cottonfibers), a combination of natural and synthetic fibers, porous foams,reticulated foams, apertured plastic films, or the like. Various wovenand nonwoven fabrics can be used for the bodyside liner 42. For example,the bodyside liner can be composed of a meltblown or spunbonded web ofpolyolefin fibers. The bodyside liner can also be a bonded-carded webcomposed of natural and/or synthetic fibers. The bodyside liner can becomposed of a substantially hydrophobic material, and the hydrophobicmaterial can, optionally, be treated with a surfactant or otherwiseprocessed to impart a desired level of wettability and hydrophilicity.For example, the material can be surface treated with about 0.45 weightpercent of a surfactant mixture including AHCOVEL® N-62 from Uniqema,Inc., a division of ICI of New Castle, Del., and GLUCOPON® 220UP fromCognis Corp. of Ambler, Pa., in an active ratio of 3:1. The surfactantcan be applied by any conventional means, such as spraying, printing,brush coating or the like. The surfactant can be applied to the entirebodyside liner 42 or can be selectively applied to particular sectionsof the bodyside liner, such as the medial section along the longitudinalcenterline.

A suitable liquid permeable bodyside liner 42 is a nonwoven bicomponentweb having a basis weight of about 27 gsm. The nonwoven bicomponent canbe a spunbond bicomponent web, or a bonded carded bicomponent web.Suitable bicomponent staple fibers include a polyethylene/polypropylenebicomponent fiber available from CHISSO Corporation, Osaka, Japan. Inthis particular bicomponent fiber, the polypropylene forms the core andthe polyethylene forms the sheath of the fiber. Other fiber orientationsare possible, such as multi-lobe, side-by-side, end-to-end, or the like.While the outer cover 40 and bodyside liner 42 can include elastomericmaterials, it can be desirable in some embodiments for the compositestructure to be generally inelastic, where the outer cover, the bodysideliner and the absorbent assembly include materials that are generallynot elastomeric.

The absorbent assembly 44 (FIG. 3) is positioned between the outer cover40 and the bodyside liner 42, which components can be joined together byany suitable means, such as adhesives, as is well known in the art. Theabsorbent assembly 44 can be any structure which is generallycompressible, conformable, non-irritating to the child's skin, andcapable of absorbing and retaining liquids and certain body wastes. Theabsorbent assembly 44 can be manufactured in a wide variety of sizes andshapes, and from a wide variety of liquid absorbent materials commonlyused in the art. For example, the absorbent assembly 44 can suitablyinclude a matrix of hydrophilic fibers, such as a web of cellulosicfluff, mixed with particles of a high-absorbency material commonly knownas superabsorbent material. High absorbency material can be provided inany form known in the art, including but not limited to particles,fibers, foams and films.

In a particular embodiment, the absorbent assembly 44 includes a matrixof cellulosic fluff, such as wood pulp fluff, and superabsorbenthydrogel-forming particles. The wood pulp fluff can be exchanged withsynthetic, polymeric, meltblown fibers or with a combination ofmeltblown fibers and natural fibers. The superabsorbent particles can besubstantially homogeneously mixed with the hydrophilic fibers or can benonuniformly mixed. The fluff and superabsorbent particles can also beselectively placed into desired zones of the absorbent assembly 44 tobetter contain and absorb body exudates. The concentration of thesuperabsorbent particles can also vary through the thickness of theabsorbent assembly 44. Alternatively, the absorbent assembly 44 caninclude a laminate of fibrous webs and superabsorbent material or othersuitable means of maintaining a superabsorbent material in a localizedarea.

Suitable superabsorbent materials can be selected from natural,synthetic, and modified natural polymers and materials. Thesuperabsorbent materials can be inorganic materials, such as silicagels, or organic compounds, such as crosslinked polymers. Suitablesuperabsorbent materials are available from various commercial vendors,such as Dow Chemical Company located in Midland, Mich., U.S.A., andStockhausen GmbH & Co. KG, D-47805 Krefeld, Federal Republic of Germany.Typically, a superabsorbent material is capable of absorbing at leastabout 15 times its weight in water, and desirably is capable ofabsorbing more than about 25 times its weight in water.

In one embodiment, the absorbent assembly 44 is generally rectangular inshape, and includes a blend of wood pulp fluff and superabsorbentmaterial. One preferred type of fluff is identified with the tradedesignation CR1654, available from U.S. Alliance, Childersburg, Ala.,U.S.A., and is a bleached, highly absorbent sulfate wood pulp containingprimarily soft wood fibers. As a general rule, the superabsorbentmaterial is present in the absorbent assembly 44 in an amount of fromabout 0 to about 90 weight percent based on total weight of theabsorbent assembly. The absorbent assembly 44 suitably has a densitywithin the range of about 0.10 to about 0.50 grams per cubic centimeter.The absorbent assembly 44 may or may not be wrapped or encompassed by asuitable tissue wrap that maintains the integrity and/or shape of theabsorbent assembly.

The absorbent chassis 32 can also incorporate other materials that aredesigned primarily to receive, temporarily store, and/or transportliquid along the mutually facing surface with the absorbent assembly 44,thereby maximizing the absorbent capacity of the absorbent assembly. Onesuitable material is referred to as a surge layer (not shown) andincludes a material having a basis weight of about 50 to about 120 gramsper square meter, and including a through-air-bonded-carded web of ahomogenous blend of 60 percent 3 denier type T-256 bicomponent fiberincluding a polyester core/polyethylene sheath and 40 percent 6 deniertype T-295 polyester fiber, both commercially available from KosaCorporation of Salisbury, N.C., U.S.A.

As noted previously, the illustrated training pant 20 has front and backside panels 34, 134 disposed on each side of the absorbent chassis 32.These transversely opposed front side panels 34 and transversely opposedback side panels 134 can be permanently bonded to the front panel 35 andback panel 135 in the respective front and back regions 22, 24 alongattachment lines 66, and are attached to one another. The side panels34, 134 may be permanently attached using attachment means known tothose skilled in the art such as adhesive, thermal or ultrasonicbonding. As mentioned, the side panels 34, 134 can also be formed ascontinuous extensions of the front and back panels 35, 135.

As shown in FIG. 1, the fastening component 82 can be permanently bondedto either the inner surface 28 or the outer surface 30 of each frontside panel 34 adjacent each distal edge 36 of the front region 22 of thechassis 32, and the mating fastening components 84 can be permanentlybonded to either the inner surface 28 or the outer surface 30 of eachback side panel 134 adjacent each distal edge 36 of the back region 24of the chassis, or either the inner surface 28 or the outer surface 30of the chassis 32 can include fastening material 86 or mating fasteningmaterial 88. The fastening components 82 and the mating fasteningcomponents 84 may be attached to the side panels 34 and the chassis 32using attachment means known to those skilled in the art such asadhesive, thermal or ultrasonic bonding.

The fastening component may comprise adhesive, cohesive, tape, hook andloop, or any other refastenable attachment means know in the art. In oneparticular embodiment, the fastening components 82 each include hooktype fasteners and the mating fastening components 84 each includecomplementary loop type fasteners. In another particular embodiment, thefastening components 82 each include loop type fasteners and the matingfastening components 84 each include complementary hook type fasteners.In yet another embodiment, half of the fastening components 82 and halfof the mating fastening components 84 can include hook type fasteners,while half of the fastening components 82 and half of the matingfastening components 84 can include loop type fasteners. In stillanother embodiment, each of the fastening components 82 and the matingfastening components 84 include self-engaging fasteners. The fasteningcomponents 82 and the mating fastening components 84 are desirablyrectangular, although they may alternatively be square, round, oval,curved, discontinuous such as multiple fasteners, or any other suitableshape. The fastening components 82 and mating fastening components 84may or may not be parallel to a longitudinal midline 94 of the garment20.

In another embodiment, the nonwoven web in the outer cover 40 can beconstructed of a material that is suitable for use as a loop-typefastening material, thereby eliminating the need for separate loop-typefastening components 82 or 84, and the fastening components 82 or 84 onthe side panels 34 or 134 can be hook-type fastening components. In yetanother embodiment, the nonwoven web in the bodyside liner 42 can beconstructed of a material that is suitable for use as a loop-typefastening material, thereby eliminating the need for separate loop-typefastening components 82 or 84, and the fastening components 82 or 84 onthe side panels 34 or 134 can be hook-type fastening components. Instill another embodiment, an inner or outer surface of either the frontside panels 34 or the back side panels 134 can include a loop-typefastening material, thereby eliminating the need for separate loop typefastening components 82 or 84.

Loop type fasteners typically include a fabric or material having a baseor backing structure and a plurality of loop members extending upwardlyfrom at least one surface of the backing structure. The loop materialcan be formed of any suitable material, such as acrylic, nylon orpolyester, and can be formed by methods such as warp knitting, stitchbonding or needle punching. Suitable loop materials are available fromGuilford Mills, Inc., Greensboro, N.C., U.S.A. under the tradedesignation No. 36549.

Hook type fasteners typically include a fabric or material having a baseor backing structure and a plurality of hook members extending upwardlyfrom at least one surface of the backing structure. In contrast to theloop type fasteners which desirably include a flexible fabric, the hookmaterial advantageously includes a resilient material to minimizeunintentional disengagement of the fastener components as a result ofthe hook material becoming deformed and catching on clothing or otheritems. Suitable hook material can be molded or extruded of nylon,polypropylene or another suitable material. Suitable single-sided hookmaterials for the fastening components 82 or the mating fasteningcomponents 84 are available from commercial vendors such as VelcroIndustries B.V., Amsterdam, Netherlands or affiliates thereof, and areidentified as Velcro HTH-829 with a uni-directional hook pattern andhaving a thickness of about 0.9 millimeters (35 mils) and HTH-851 with auni-directional hook pattern and having a thickness of about 0.5millimeters (20 mils); and Minnesota Mining & Manufacturing Co., St.Paul, Minn. U.S.A., including specific materials identified as CS-600.

In particular embodiments for improved fit and appearance, the sidepanels 34, 134 desirably have an average length dimension measuredparallel to the longitudinal axis 48 that is about 15 percent orgreater, and particularly about 25 percent or greater, of the overalllength dimension of the absorbent article, also measured parallel to thelongitudinal axis 48. For example, in training pants having an overalllength dimension of about 54 centimeters, the side panels 34, 134desirably have an average length dimension of about 10 centimeters orgreater, such as about 15 centimeters. A waist end edge 72 of each sidepanel 34, 134 can suitably be relatively straight across in thetransverse direction while the leg end edge 70 of each side panel 34,134 can suitably have a curvature, as shown in FIGS. 2 and 3, to allowthe leg opening 52 to conform about a wearer's leg.

Each of the side panels 34, 134 can include one or more individual,distinct pieces of material in addition to the fastening components 82,84, as shown in FIG. 3. In particular embodiments, for example, eachside panel 34, 134 can include first and second side panel portions thatare joined at a seam, with at least one of the portions including anelastomeric material. The side panels 34, 134 desirably include anelastic material capable of stretching in a direction generally parallelto the transverse axis 49 of the training pant 20. The front side panels34 and the back side panels 134 can be of equal widths or of differentwidths in the transverse direction.

Suitable elastic materials, as well as one described process ofincorporating elastic side panels into a training pant, are described inthe following U.S. Pat. No. 4,940,464 issued Jul. 10, 1990 to Van Gompelet al.; U.S. Pat. No. 5,224,405 issued Jul. 6, 1993 to Pohjola; U.S.Pat. No. 5,104,116 issued Apr. 14, 1992 to Pohjola; and U.S. Pat. No.5,046,272 issued Sep. 10, 1991 to Vogt et al.; all of which areincorporated herein by reference. In particular embodiments, the elasticmaterial includes a stretch-thermal laminate (STL), a neck-bondedlaminated (NBL), a reversibly necked laminate, or a stretch-bondedlaminate (SBL) material. Methods of making such materials are well knownto those skilled in the art and described in U.S. Pat. No. 4,663,220issued May 5, 1987 to Wisneski et al.; U.S. Pat. No. 5,226,992 issuedJul. 13, 1993 to Morman; and U.S. Pat. No. 4,720,415 issued Feb. 2, 1992to Taylor et al.; all of which are incorporated herein by reference.Alternatively, the side panel material may include other woven ornonwoven materials, such as those described above as being suitable forthe outer cover 40 or bodyside liner 42, or stretchable but inelasticmaterials.

FIG. 4 illustrates a view of a training pant 20 including a refastenablebond 83 and a releasable bond 96 of the present invention. The trainingpant 20 includes a fastening component 82 disposed in a first waistregion, specifically as shown attached to the front side panel 34. Thetraining pant 20 also includes a mating fastening component 84 disposedin the second waist region, specifically as shown attached to the backside panel 134. The fastening components 82, 84 define a refastenablebond 83. The training pant 20 also includes a releasable bond 96, whichbonds a portion of the front side panel 34 to a second portion of thefront side panel 34 maintaining a fold 102 in the front side panel 34.The fold 102 and releasable bond 96 are positioned such that thefastening component 82, while disposed on the outer surface of the frontpanel 34, faces the inner surface 28 of the back side panel 134.

This arrangement of bonds 83, 96 and fold 102 may provide many benefits,first of which may be ease of manufacture. During manufacture, thetraining pant 20 may be constructed from a flat elongated web. Thereleasable front side panel 34 may be folded and releasably bonded 96.The fastening components 82, 84 may then be placed on the side panels34, 134 (both applied from the inner surface 28 side of the elongatedweb). The elongate web may then be cut into discrete articles. To formthe closed training pant 20, the discrete article is folded along thetransverse axis 49 bringing the front side panel 34 and rear side panel134 into face to face contact, forming a refastenable bond 83 with thefastening components 82, 84.

FIG. 4A illustrates a view of a training pant 20 including arefastenable bond 83 and a releasable bond 96 of the present inventionafter the front waist region 90 has been separated from the back waistregion 92. As illustrated in FIG. 4, separating the front waist region90 from the back waist region 92 initially stresses the refastenablebond 83 and the releasable bond 96 predominantly in peel. Furtherseparation of the waist regions 92, 94 ruptures the releasable bond 96predominantly in peel (releasable bond after rupture 100). Continuedseparation of the waist region 92, 94, stresses the refastenable bond 83predominantly in shear. The arrangement of the releasable bond 96,refastenable bond 83 and fold 102, may provide great benefits in themanufacture, strength and aesthetics of refastenable bond 83.

One way to construct the combination of side panels 34, 134 is byutilizing bonds 82, 84, 96 with the appropriate relative peel strengths.The peel strength of the refastenable bond 83 may be chosen to begreater than the peel strength of the releasable bond 96. The ratio ofthe refastenable bond peel strength to the releasable bond peel strengthmay be greater than 1.5, alternatively greater than 5, alternativelygreater than 10, alternatively greater than 25, alternatively greaterthan 50.

The releasable bond 96 may include ultrasonic bonding, pressure bonding,thermal bonding, adhesive bonding, cohesive bonding, magnetic bonding orany combination thereof. The releasable bond 96 may also include hookand loop. The releasable bond 96 may be chosen such the releasable bondafter rupture 100 is skin friendly as contact with a wearer's skin ispossible.

Peel Strength Test

This procedure is a tensile bench test to measure the peel forcerequired to separate a mechanical fastening system that joins twomaterials. The peel force of separation is measured by determining loadvalues as the two materials are pulled apart perpendicular to theirplane of contact. The direction of removal (peel), in this application,is that direction in which the fastener material would generally beremoved from a substrate when the product is in use. Peel strength isnormalized by dividing by the contact area resulting in a force perarea.

Equipment

1. Tensile tester capable of obtaining a peak load and equipped with anappropriate load cell. A suitable tensile testing system is a SintechTensile Tester, commercially available from MTS Sintech, ResearchTriangle Park, N.C., under the trade designation Instron Model 4201Tensile Tester with Sintech QAD (Quality Assurance Department) Software.

2. Software commercially obtained from MTS Sintech under the tradedesignation Sintech Testworks®.

3. Pneumatic-action grips commercially available from InstronCorporation, Canton, Mass., under the trade designation “Instron Model2712-004.”

4. 1 by 4 inch grip faces, serrated, commercially available from InstronCorporation, Canton, Mass.

5. Test facility having a temperature of 23±1° C., and a relativehumidity of 50±2 percent.

Test Procedure

1. A sample to be tested is conditioned in the test facility for atleast 4 hours prior to testing.

2. The load cell is calibrated and the software loaded.

3. The grips are installed on the tensile tester with the jaws closed.

4. The test condition for the tensile tester is set as follows:

Crosshead speed=500 millimeters/minute

Full-scale load=5 kilograms;

Threshold=5 percent;

Fail criterion=95 percent; and

Gage length=50 millimeters.

5. The weight of the clamp is tared out.

6. The ear portion on the back waist region of the article is insertedinto the upper jaw such that the edge of the grip face is flush with theinner edge of the fastener material.

7. The front waist region of the article is inserted into the lower jawsuch that the inner surface of the back waist region and the outersurface of the front waist region form a 180° angle. The lower jaw isclosed.

8. The crosshead is started in motion.

9. The peak load of failure is recorded. It is intended that the mode offailure is that the back waist region of the diaper separates from thefront waist region of the diaper.

FIG. 5 illustrates a view of a training pant 20 including a refastenablebond 83, permanent bond 98 and a releasable bond 96 of the presentinvention. The training pant 20 includes a fastening component 82attached to the chassis and disposed in a first waist region,specifically as shown attached to the front side panel 34. The trainingpant 20 also includes a mating fastening component 84 attached to thechassis and disposed in the second waist region, specifically as shownattached to the back side panel 134. The fastening components 82, 84define a refastenable bond 83. The training pant 20 also includes areleasable bond 96, which bonds a portion of the front side panel 34 toa second portion of the front side panel 34 maintaining a fold 102 inthe front side panel 34. The fold 100 and releasable bond 96 arepositioned such that the fastening component 82, while disposed on theouter surface of the front panel 34, faces the inner surface 28 of theback side panel 134. The training pant 20 also includes a permanent bond98, which bonds a portion of the back side panel 134 to a second portionof the back side panel 134 maintaining a fold 104 in the back side panel134. The fold 104 and permanent bond 98 are positioned such that thefastening component 84, while disposed on the outer surface 30 of theback panel 134, faces the inner surface 28 of the front side panel 34.

The inclusion of the permanent bond 98 and fold 104 may provideadditional benefits with regard to manufacture. The permanent bond 98and fold 104 may be positioned such that width of the back side band 134is reduced by the same amount as the width of the front side panel 34 isreduced by the releasable bond 96 and fold 102. If original width of theside panels 34, 134 is the same, this equal reduction may simplify themanufacturing process by aligning the fastening components 82, 84 whenthe training pant 20 is folded along the transverse axis 49 withoutfurther manipulation of the side panels 34, 134.

FIG. 5A illustrates a view of a training pant 20 including arefastenable bond 83, a permanent bond 98 and a releasable bond 96 ofthe present invention after the front waist region 90 has been separatedfrom the back waist region 92. As illustrated in FIG. 5, separating thefront waist region 90 from the back waist region 92 initially stressesthe refastenable bond 83, the permanent bond 96 and the releasable bond96 predominantly in peel. Further separation of the waist regions 92, 94ruptures the releasable bond 96 predominantly in peel (releasable bondafter rupture 100). Continued separation of the waist region 92, 94,stresses the refastenable bond 83, and permanent bond 96 predominantlyin shear. The arrangement of the releasable bond 96, permanent bond 98,refastenable bond 83, and folds 102, 104, may provide great benefits inthe manufacture, strength and aesthetics of releasable seam 80. Thepermanent bond 98 and fold 104 provides the added benefit in that theterminal end 106 of the back side panel 134 is not visible from theoutside of the training pant 20, thereby presenting a more finishedlooking appearance.

The peel strength of the permanent bond 98 may be chosen to be greaterthan the peel strength of the releasable bond 96. The peel strength ofthe permanent bond 98 may be chosen to be greater than the peel strengthof the refastenable bond 83. The ratio of the permanent bond peelstrength to the releasable bond peel strength may be greater than 1.5,alternatively greater than 5, alternatively greater than 10,alternatively greater than 25, alternatively greater than 50.

The permanent bond 98 may include ultrasonic bonding, pressure bonding,thermal bonding, adhesive bonding, cohesive bonding, magnetic bonding orany combination thereof. The permanent bond 98 may also include hook andloop.

FIGS. 6A-D illustrate several seams joining a first material 110 havinga first end 112 and a second end 114 and a second material 116 having athird end 118 and fourth end 120, specifically the first end 112 of thefirst material 110 to the third end 118 of the second material 116.FIGS. 6A and 6B illustrate butt seams. FIG. 6A illustrates a seam aspreviously known in the art. As used herein, the term “butt seam” refersto a seam or bond where the outer edges of the pieces of substrateproject inward or outward from the finished product, as opposed to lyingflat, thus placing the bond (122 in FIG. 6A, 122 and 124′ in FIG. 6B) inpeel, as opposed to shearing strain. FIG. 6B illustrates a combinationof a refastenbable bond 122, and a releasable bond 124 which join afirst end 112 of a first material 110 to a third end 118 of a secondmaterial 116. The first material 110 is folded and bonded with thereleasable bond 124.

Separating the second end 114 of the first material 110 from the fourthend 120 of the second material 116 initially stresses the refastenablebond 122 and the releasable bond 124 predominantly in peel, thenruptures the releasable bond 124 predominantly in peel, then stressesthe refastenable bond 122 predominantly in shear.

FIGS. 6B through 6D illustrate the conversion of a butt seam into a lapseam. The releasable bond 124 has a lower peel strength thanrefastenable bond 122; consequently, as force is applied to thecombination of bonds 122, 124, releasable bond 124 will fail first. Uponfailure of releasable bond 124, refastenable bond 124 is converted intoa lap seam, thus placing the refastenable bond 124 in shear as opposedto peel strain.

It will be appreciated that details of the foregoing embodiments, givenfor purposes of illustration, are not to be construed as limiting thescope of this invention. Although only a few exemplary embodiments ofthis invention have been described in detail above, those skilled in theart will readily appreciate that many modifications are possible in theexemplary embodiments without materially departing from the novelteachings and advantages of this invention. Accordingly, all suchmodifications are intended to be included within the scope of thisinvention, which is defined in the following claims and all equivalentsthereto. Further, it is recognized that many embodiments may beconceived that do not achieve all of the advantages of some embodiments,particularly of the preferred embodiments, yet the absence of aparticular advantage shall not be construed to necessarily mean thatsuch an embodiment is outside the scope of the present invention.

1. A refastenable joint joining a first material having a first end anda second end to a second material having a third end and a fourth end,including a refastenable bond connecting the first end to the third end,the first material being folded and bonded with a releasable bondwherein separating the second end from the fourth end initially stressesthe refastenable bond and the releasable bond predominantly in peel,then ruptures the releasable bond predominantly in peel, then stressesthe refastenable bond predominantly in shear.
 2. The joint of claim 1,wherein the third end is folded and bonded with a permanent bond,separating the second end from the fourth end initially stresses thepermanent bond, refastenable bond and the releasable bond in peel, thendestroys the releasable bond in peel, then stresses the refastenablebond and permanent bond in shear.
 3. The joint of claim 2, wherein thepermanent bond comprises an ultrasonic bond.
 4. The joint of claim 1,wherein the releasable bond has a releasable bond peel strength, thepermanent bond has a permanent bond peel strength and the refastenablebond has a refastenable bond peel strength, the releasable bond peelstrength is less than the refastenable bond peel strength, and therefastenable bond peel strength is less than the permanent bond peelstrength.
 5. The joint of claim 4, wherein a ratio of the refastenablebond peel strength to the releasable bond peel strength is greater than1.5.
 6. The joint of claim 4, wherein the ratio of the refastenable bondpeel strength to the releasable bond peel strength is greater than 50.7. The joint of claim 1, wherein the refastenable bond comprises hookand loop, cohesive, adhesive or tape.
 8. The joint of claim 1, whereinthe releasable bond comprises an ultrasonic bond.
 9. The joint of claim1, wherein the releasable bond comprises a pressure bond.
 10. The jointof claim 1, wherein the releasable bond comprises an adhesive bond.